AC O-Rings confusion..

[saneesh8]

The realoem is confusing so i thought of buying the kit from other vendors instead of the dealer. I found

Pelican - http://www.pelicanparts.com/cgi-bin/...0Seal%20Kit%22

Rock Auto - http://www.rockauto.com/catalog/rafr...ttype=13290&ck[ID]=0&ck[idlist]=0&ck[viewcurrency]=USD&ck[PHP_SESSION_ID]=qfna0288toaih41ibc99r66667

NAPA - http://www.napaonline.com/Catalog/Ca...793_0158875790

Real OEM -
http://www.realoem.com/bmw/showparts...17&hg=64&fg=60, items 6,7,8,9
and
http://www.realoem.com/bmw/showparts...60&hg=64&fg=30, items 3,4,5,6

Which is the right one? Mainly the ORings on the Expansion valve, it is confusing. Others are 11.1mm or 14mm. (i think 3 X 14mm and 5 X 11.1mm)

Have a very slow leak. Like need to charge it once a year. Replaced the expansion valve and the dryer last year, but could not replace all the O-Rings at that time.

Also the Compressor is kind of week and also make a whining noise. Do i have to replace the PAG100 oil inside (like 6 oz or something).

After the last fix it had , new expansion valve and Drier and some O-Rings(90-95F with 45% humidity, warm engine). Looked ok and was cooling enough (not so great as other cars)
At idle it was 50 PSI on low and 220 PSI on high.
At 1500 rpm it is 32PSI and 265PSI
At 2500 rpm, it is 23 PSI on low and 285 PSI on high

[Blacklane]

Usually, things like expansion valves, receiver/dryers, etc., come with the proper O-rings. Certainly you should use those whenever available. Also always lubricate them with PAG oil before installing them.
I have a few of those A/C O-ring assortments and have always found the one I need, when needed. With the actual sizes specified in RealOEM.com, you could also just buy those (e.g.: D=11mm). (Note that with European nomenclature, a comma is used as a decimal point, unlike the in the US).
The entire system uses 6-oz of PAG-100 oil, but much of that is spread throughout the other components. If possible, it's best to pour the oil out of the old compressor into a plastic cup, then mark the level. Add this much back into the new compressor, plus a little more to account for the tiny bit still in the old compressor. There might be some "shipping oil" in the new compressor. Drain this out and use it as part of the replacement oil measurement.
Your pressures look just about right. Note when filling the system, the Z3 compressor is a variable-displacement compressor. This makes it hard to fill based on pressures alone and your system might be a little over-filled. I have had much more success by filling based on refrigerant weight as specified on the green label under the hood. I have a small digital scale that I use after subtracting the weight of the full can and hoses.

[saneesh8]

Thanks Blacklane.

Because it was urgent, last year when i replaced, i used the O-Rings came with the Expansion valve (bought from Autozone) and Drier (bought from NAPA). The Autozone ORings were clearly skinny ones, same diameter but not wide as the original one and started leaking immediately as soon as put it in. So i reused the old one. For Drier, i used the one which came with it. I used the oil which came out of the old R134a can (the one which comes with oil) on the ORings before putting it in.

When i filled it, i used the 900 g method by first putting 2 cans full and then (340 X2 ) rest by using a digital postal weight machine.

My plan is to buy the Pelican Parts version or OEM if possible. Then remove compressor, clean it, drain oil and and measure it, then refill with new and then clean the condensor and lines. After that all of them new ORings coated with PAG 100. Use new Drier and then vacuum it, test for leaks and fill it by weight.

The compressor, looks like i can reuse it? Since the pressure is ok?

The ORings around the Expansion valve, since the ORings comes with it were completely wrong type, i really need to replace them with new ones. All the others except these ORings, easy to find and buy. The real OEM part numbers, is it ok?

Thanks a lot in advance.

[Vinci]

When I replaced my evaporator/drier/expansion valve, I bought the whole set of o-rings from the dealer. You pay more (probably a LOT more) for them, but you can be sure that they are correct. I didn't want to do the job twice, so I just bit the bullet and spent the extra couple bucks up front.

Whenever you are recharging, you should assume that you've lost some oil. How much is hard to say without opening the system and measuring all that is still in there, which is just about impossible. If you haven't been putting oil in there, you should be. That could be a reason (in my mind) that your compressor is noisy or (now) worn.

[saneesh8]

Vinci- From the dealership, did you buy them by looking at the part numbers as per the real oem? Somewhere i read that the number or ORing size may not match realoem? Even for me too, i really want to buy the best and don't look back.

From http://www.realoem.com/bmw/showparts...17&hg=64&fg=60
64508390603 X3 (14mm)
64508390602 X5 (11.1mm)
http://www.realoem.com/bmw/showparts...60&hg=64&fg=30 (at expansion valve)
64506904701-1
64506904700-1
64508369241-1
64508369240-1

Yes, you are right. I didn't fill in any oil, but i used some can with oil in it (which says PAG oil inside). Hope it is fine. Whine is not audible in the car, only when standing in the front of the car.

[328 Power 04]

You should get a set of 20+ variety of o rings from Autozone/Advance auto, etc, and match them for fitment. I think the 100 pack is about $20, and they will work great.

[Vinci]

Vinci- From the dealership, did you buy them by looking at the part numbers as per the real oem? Somewhere i read that the number or ORing size may not match realoem? Even for me too, i really want to buy the best and don't look back.

From http://www.realoem.com/bmw/showparts...17&hg=64&fg=60
64508390603 X3 (14mm)
64508390602 X5 (11.1mm)
http://www.realoem.com/bmw/showparts...60&hg=64&fg=30 (at expansion valve)
64506904701-1
64506904700-1
64508369241-1
64508369240-1

Yes, you are right. I didn't fill in any oil, but i used some can with oil in it (which says PAG oil inside). Hope it is fine. Whine is not audible in the car, only when standing in the front of the car.

I bought by part number and quantity from RealOEM, yes. This was 2-3 years ago, mind you, but I don't think that info has changed. I bought extras as well, since I didn't want to be neck-deep in the project and be stuck because I cut an o-ring.

[saneesh8]

I tried to call the local dealership to check. Seems there are so busy and the parts department is not taking the phone call. So checked with Autozone and found a kit with lots of O-Rings specifically for AC and the manufacturer says it is valid for the Z3 (Santech). Ordered it (it was special order) and should get it today. Waiting for their call now.

If i don't get it by today evening, planning to visit the dealership directly. Not far away, but most of the time, they will tell me to come back on another day since they don't have it in stock. Like when i tried to order the DISA valve, they said 2 weeks and got it online in less than a week.

328 Power 04, This is what i ordered from Autozone - http://www.autozone.com/autozone/par...mString=search

I think you were taking about this? http://www.autozone.com/autozone/acc...er=271196_0_0_

[djb2]

I've never found a kit that was actually for a specific BMW model. Many claim to be, but they are just selling a high-priced generic assortment.

I suggest buying individual o-rings from autohausaz.com. It's far less expensive and you'll get correctly sized HNBR o-rings.

A few years ago I tried to buy BMW o-rings. I went to every BMW dealer in the Washington DC area. In July. For those that don't understand, it's hot there and it's not a dry heat. If there is any place and time of year that a dealer should stock o-rings, this is it.

Only one of the dealers had o-rings, and they weren't BMW parts. The guy behind the parts counter went searching through an assortment of random o-rings he happened to have there, and located two sizes of the four sizes I asked for. For which I was charged BMW list price. (BTW, they turned out to be not quite the right size.)

From this I conclude that most dealers just re-use the old o-rings. Which probably works most of the time, but is a bad deal for the customer when service is $120/hour.

[saneesh8]

Hi djb2..

I got into some other issues which affects the cars movement it self. Seems like the Throttle body or DME. So postponed this till i fix that one.

I had to reuse the ORings at the expansion valve last time because the new one which came with expansion valve was completely different size.

Thanks.

[saneesh8]

Finally i bought the assortment pack from autozone (like 328 power04 suggested) and replaced

O-Rings at Drier - size matched as per real oem.
O-Rings at Expansion valve - http://www.realoem.com/bmw/showparts...60&hg=64&fg=30. Item 3 was wrong size listed in real oem. It is not 7mm ID. Some thing like 9 or 10mm from the pack. Matched it by fitment. All the others, matched by real oem
O-Rings at double pipe - http://www.realoem.com/bmw/showparts...17&hg=64&fg=60. Items 6 and 7. One was 11.1 and other was smaller. Matched by fitment. Not matching real oem size

Need to change it at compressor and condenser.

Anyway i did a vacuum check and it was holding it for more than 12 hours (left it with vacuum and went to sleep). Today changing at Compressor and condenser.

Wonder why realoem does not match with actual. I measured the ID as indicated. Luckily matching by size seems to be working. Did anyone else got into this dilemma?

[ZoO]

i spent all weekend battling with the wrong o ring sizes from realoem. pretty much everything from firewall forward was wrong.